Results 271 to 280 of about 40,603 (292)

Meteorological Focusing of Acoustic Energy

Sound: Its Uses and Control, 1963
Meteorological focusing of acoustic energy by calculating acoustic ray paths, to be used as a method of noise ...
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Self-focused acoustic ejectors for viscous liquids

Review of Scientific Instruments, 2010
Self-focused acoustic ejectors using the Fresnel zone plate (FZP) have been developed for ejecting viscous liquids, without nozzle, in the drop-on-demand mode. The FZP is composed of a lead zirconate titanate piezoelectric plate patterned with a series of annular electrodes, with the unelectroded region of the plate removed.
Hon, SF, Kwok, KW, Li, HL, Ng, HY
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Bidirectional asymmetric acoustic focusing with two flat acoustic metasurfaces

Chinese Physics B, 2018
We design an asymmetric transmission system (ATS) with two flat acoustic metasurfaces (AMs) to yield bidirectional asymmetric acoustic focusing (BAAF). The acoustic waves could be focused on both sides of the ATS with different focal lengths and intensities. To achieve high intensity energy concentration, the accelerating acoustic beams are selected to
Di-Chao Chen, Xing-Feng Zhu, Qi Wei, Da-Jian Wu   +3 more
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The Effects of Phase-Modulated Excitation on the Focused Acoustic Field

IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control, 2020
Various modulation approaches, such as amplitude and frequency modulations, have been applied widely to modify the acoustic field and improve the performance of ultrasound imaging and therapy. However, phase modulation (PM) has not been investigated extensively in the ultrasound applications, especially at a long-pulse duration.
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Optimum acoustic frequency for focused ultrasound surgery

Ultrasound in Medicine & Biology, 1994
A model is described that enables calculation of ultrasound lesioning rate (inverse of time to achieve a threshold lesion in the absence of thermal redistribution) as a function of acoustic frequency, tissue penetration depth, d, attenuation coefficient at specific frequency, mu, and power of dependence of attenuation on frequency, n.
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Squeezing of a Focused Acoustic Beam and Acoustic Microscopy of Anisotropic Media

Japanese Journal of Applied Physics, 1995
The concept of squeezing in quantum optics is applied to focused acoustic beam evaluation for the first time. Mathematical equivalence between coherent and squeezed states in quantum optics and angular spectra in various acoustical imaging schemes is derived and discussed.
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Acoustic metamaterials with near-zero density effects for acoustic focusing

Journal of Vibration and Control
Acoustic focusing technology has demonstrated significant application prospects across multidisciplinary fields. Based on the principle of fractal self-similarity, this study proposes a novel fractal acoustic metamaterial. Calculations of equivalent acoustic parameters reveal that this structure exhibits near-zero density effects at frequencies of 2271 
He Chuan, Feng Feifei, Diao Lei, Tao Meng   +3 more
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Acoustic focusing of microplastics in microchannels: A promising continuous collection approach

Sensors and Actuators B: Chemical, 2020
Yoshitake Akiyama, Hiroshi Moriwaki, Yoshitake Akiyama   +2 more
exaly  

Observation of Ultrabroadband Acoustic Focusing Based on V‐Shaped Meta‐Atoms

Advanced Materials Technologies, 2020
Jiao Qian, Yong Ge, Shou-Qi Yuan
exaly  

Acoustic focusing by coiling up space

Applied Physics Letters, 2012
Yong Li, Bin Liang, Xue-Feng Zhu
exaly